Avalanche Forecast

Issued: Dec 15th, 2019 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Deep Persistent Slabs and Wind Slabs.

Parks Canada william lawson, Parks Canada

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Basal facets, crusts and depth hoar are found in many places. Use caution if you're heading into committing terrain, as it's a bit of a gamble whether you will trigger a slope, these layers are hard to predict.

Summary

Weather Forecast

A gradual increase in wind values beginning Sunday afternoon will result in sustain strong winds at upper elevations. Wi will likely see an increase in cloud cover Monday and light precipitation by Tuesday. A slight warming trend will begin early Monday with valley bottom temperatures climbing to the negative single digits.

Snowpack Summary

Pockets of wind slab linger in alpine areas. Beneath the recent 40-60cm of storm snow, the snowpack structure is generally weak, consisting of facets and depth hoar. The Nov crust is present up to 2500m and ~30 cm up from ground. In areas with a deeper snowpack (Tak Falls, Stanley Mitchell, Ogden, etc.) the basal weakness is less pronounced.

Avalanche Summary

No new natural avalanche activity observed or reported Sunday.

Confidence

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The recent snow sits over weak facet and crust layers. As time goes on the chance of triggering is becoming less likely, but there is lots of uncertainty as to where you could trigger an avalanche and what it will take to get it moving.

  • Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

An icon showing Wind Slabs

Variable wind slab development is present mainly in the alpine but also in some wind exposed treeline features. These are losing sensitivity to human triggering but will need a few days to settle out completely.

  • Use caution in lee areas. Recent wind loading has created slabs over weaker snow.
  • Caution on open steep slopes at treeline that have been exposed to wind loading.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 16th, 2019 4:00PM